The analysis of brain ventricles (BVs) is important in the study of normal and abnormal development of the central nervous system. The mouse has been used as a model to study mammalian development because of the high degree of homology between the mouse and human genome. Studying how mutations manifest themselves during embryonic development in mice assists in the study of the human central nervous system. Real time imaging modalities and automated image processing methods are needed in such studies.
Magnetic resonance imaging (MRI), high frequency ultrasounds (HFU) and other imaging methods have become common imaging tools for imaging the developing mouse embryo. Each imaging method provides information about physical properties of tissue, but the image contrast differs. HFU provides fine-resolution, non-invasive images with real-time dynamic information. Image segmentation of the BVs in HFU or other chosen imaging modality can be difficult and time consuming, particularly if some portions of boundaries are missing. A method for accurately and automatically segmenting such images is taught in the Patent Application titled “Method of Automatic Tissue Segmentation of Medical Images” by the present inventors filed on Jan. 23, 2017, and is hereby incorporated by reference in its entirety. This teaches an automatic segmentation method called nested graph cut (NGC) and is effective for segmenting multiple nested objects in 2D or 3D images. NGC provides accurate image segmentation even when the objects have missing boundaries. NGC automatically segments BVs, head, amniotic fluid and uterus in images of mouse embryos.
A space sweeping method to separate a 3D polygon mesh into components was proposed in “Decomposing Polygon Meshes for Interactive Applications,” by Li et. al. In the proposed space sweeping method, the area profile of cross sections perpendicular to the sweep path are obtained. (The sweep path is defined by the skeleton of a target polygon mesh). A boundary between two adjacent components is then determined by analyzing the derivatives of the profile along the skeleton. However, the cross sectional area may be inconsistent along the sweeping path with a sharp turn. Such sharp turns may occur in single components of BVs, and therefore such a method may not provide accurate results.